1. Field of the Invention
The present invention relates to a starter motor and more particularly to a starter motor wherein a one-way clutch unit which is carried on and around an output shaft so as to be slidable is slided by a shift lever.
2. Discussion of Background
A conventional starter motor which has been used to start a vehicle engine is constructed as shown in FIG. 2.
The conventional starter motor 1 is constituted by a D C motor 2, a one-way clutch unit 4 carried on and around an output shaft 3 so as to be slidable, a planetary reduction gear unit 5 for reducing the torque of the armature shaft 2a of the motor 2 and transmitting the reduced torque to a clutch outer 4a of the one-way clutch unit 4, a solenoid switch unit 6 which is arranged at one side of the motor 2 to slide the one-way clutch unit 4 on the output shaft 3, and a shift lever 8 which has one end engaged with a hook 6a held by a plunger of the solenoid switch unit 6, and the other end engaged in a perpheral annular groove of an annular member 7 attached to the one-way clutch unit 4.
In the conventional starter motor 1, the rocking fulcrum 8a about which the shift lever 8 is rocked to slide the one-way clutch unit 4 on the output shaft 3, and an upper end 8b of the shift lever engaged with the hook 6a are positioned ahead of (in FIG. 2, at the right side of) the vertical line 9 passing through the lower end 8c of the shift lever. This creates a problem wherein the distance between an engine a mounting surface 10 of the starter motor and a pinion 11 in the retracted position, which is integral with the clutch inner 4b, is short, and the starter motor is, therefore, not applicable to a vehicle engine having a long distance between its engine mounting surface and its ring gear.